Effect of 4-Hydroxy-2-Nonenal Modification on Alpha-Synuclein Aggregation

Journal Article · Thu Jul 12 04:00:00 EDT 2007 · J. Biol. Chem. 282:5862,2007

DOI:https://doi.org/10.1074/jbc.M608126200· OSTI ID:909756

Qin, Z; Hu, D; Han, S; Reaney, S H; Monte, D A Di; Fink, A L

Several observations have implicated oxidative stress and aggregation of the presynaptic protein alpha-synuclein in the pathogenesis of PD. alpha-Synuclein has been shown to have affinity for unsaturated fatty acids and membranes enriched in PUFAs, which are especially sensitive to oxidation under conditions of oxidative stress. One of the most important products of lipid oxidation is 4-hydroxynonenal (HNE), which has been implicated in the pathogenesis of Parkinson's disease. Consequently we investigated the effects of the interaction of HNE with alpha-synuclein. Incubation of HNE with alpha-synuclein at pH 7.4, 37oC resulted in covalent modification of the protein, with up to six HNE molecules incorporated as Michael addition products. FTIR and CD spectra indicated that HNE modification of alpha-synuclein resulted in a major conformational change involving increased beta-sheet. HNE modification of alpha-synuclein led to inhibition of fibrillation in an HNE-concentration-dependent manner. This inhibition of fibrillation was shown to be due to the formation of soluble oligomers based on SEC HPLC and AFM data. Small-angle X-ray scattering analysis indicated that the HNE-induced oligomers are compact and tightly packed. Treatment with guanidinium chloride (GuHCl) demonstrated that the HNE-induced oligomers were very stable with an extremely slow rate of dissociation. Addition of 5 uM HNE-modified oligomers to primary mesencephalic cultures caused marked neurotoxicity, since the integrity of dopaminergic and GABAergic neurons was reduced by 95% and 85%, respectively. Our observations indicate that HNE-modification of alpha-synuclein prevents fibrillation but may result in toxic oligomers which could therefore contribute to the demise of neurons subjected to oxidative damage.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 909756
• Report Number(s): SLAC-REPRINT-2007-134
• Journal Information: J. Biol. Chem. 282:5862,2007, Journal Name: J. Biol. Chem. 282:5862,2007
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AFFINITY
CHLORIDES
CONFORMATIONAL CHANGES
DISSOCIATION
HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
INCUBATION
LIPIDS
MEMBRANES
MODIFICATIONS
OXIDATION
Other
OTHER
PATHOGENESIS
PROTEINS
SCATTERING
SPECTRA